feat: add new activeLoops getter (#1)

Author: ivodolenc

README.md

@@ -30,7 +30,7 @@
 - API-Friendly
 
 <blockquote>
-  <sub><strong>Package size</strong>: <code>~1.44 KB</code> minified, <code>~790 B</code> gzip</sub>
+  <sub><strong>Package size</strong>: <code>~1.54 KB</code> minified, <code>~855 B</code> gzip</sub>
 </blockquote>
 
 ## Core Concepts
@@ -230,6 +230,9 @@ By default, the callback will only be executed once.
 
 ```ts
 frame.update((state) => console.log(state), { loop: true })
+
+// The number of active frame loops can also be accessed via the `.activeLoops` getter
+console.log(frame.activeLoops)
 ```
 
 ### schedule

src/index.ts

@@ -92,7 +92,9 @@ export function createFrame<T extends string = PhaseIDs>(
   } = options
 
   const phases = {} as Record<T, Phase>
-  const loops = new Set<PhaseCallback>()
+
+  let loops = new WeakSet<PhaseCallback>()
+  let activeLoops: number = 0
 
   let tickerId: number | null = null
   let shouldRunTicker: boolean = false
@@ -129,7 +131,10 @@ export function createFrame<T extends string = PhaseIDs>(
         { loop, schedule = true }: PhaseScheduleOptions = {},
       ): PhaseCallback => {
         const queue = isRunning && !schedule ? thisFrame : nextFrame
-        if (loop) loops.add(callback)
+        if (loop) {
+          if (!loops.has(callback)) activeLoops++
+          loops.add(callback)
+        }
         if (!queue.has(callback)) queue.add(callback)
         return callback
       },
@@ -154,6 +159,7 @@ export function createFrame<T extends string = PhaseIDs>(
       },
       cancel: (callback: PhaseCallback): void => {
         nextFrame.delete(callback)
+        if (loops.has(callback)) activeLoops--
         loops.delete(callback)
       },
       clear: (): void => {
@@ -198,7 +204,7 @@ export function createFrame<T extends string = PhaseIDs>(
     const now = performance.now()
     const time = now - totalPausedTime
 
-    shouldRunTicker = loops.size > 0
+    shouldRunTicker = activeLoops > 0
 
     if (fps) {
       const delta = time - lastFrameTime
@@ -255,13 +261,18 @@ export function createFrame<T extends string = PhaseIDs>(
     },
     clear: (): void => {
       state = defaultState()
+      loops = new WeakSet()
+      activeLoops = 0
       phase((id) => id.clear())
       cancelTicker()
       shouldRunTicker = false
     },
     get state(): Readonly<FrameState> {
       return state
     },
+    get activeLoops(): Readonly<number> {
+      return activeLoops
+    },
   } as Frame<T>
 
   framePhases.forEach((id) => {

src/types.ts

@@ -136,6 +136,18 @@ export type Frame<T extends string> = {
    * ```
    */
   get state(): Readonly<FrameState>
+  /**
+   * Provides a read-only number of active frame loops at any given point.
+   *
+   * Useful for debugging and monitoring or for dynamic actions.
+   *
+   * @example
+   *
+   * ```ts
+   * frame.activeLoops
+   * ```
+   */
+  get activeLoops(): Readonly<number>
 } & FramePhases<T>
 
 export type TickerIDs = 'raf' | 'timeout'